How Marijuana Works

David G. Ostrow (Medical Marijuana Doctor) gives expert video advice on: What is 'marijuana'?; How long does it take for marijuana to affect the body once inhaled?; What causes a marijuana 'high'? and more...

What is 'marijuana'?

Marijuana, or cannabis, is an indigenous plant that's been known and written about and characterized since before Christ, several thousand years A.D. It grows in the wild, usually in warmer climates, jungles, and so forth and was discovered to be useful for treating nausea, vomiting, lack of appetite, and so forth, in the beginning and cultivated. And now we have basically two major strains of cannabis, they have somewhat different, but overlapping chemical compositions, of the compounds in them. A lot of other breeding has been done to manipulate the concentrations of specific psychoactive compounds, all of which are called cannabinoids, because they come from cannabis. And also to manipulate the strength and potency of those compounds.

How long does it take for marijuana to affect the body once inhaled?

The time for psychoactive properties is totally dependant on the route of administration. Like so many other drugs that are smoked, if, once the vaporized or smoke material enters the lungs, in very quickly enters the blood stream-- the pulmonary blood stream-- and is in the brain and is active within minutes, but its effects can last for several hours. If eaten, like at least one FTA approved compound, namely Cannabidiol, then it has be absorbed from the stomach, it has to pass through the liver, where a lot of it is metabolized, and it only reaches the brain after a considerable length of time, usually 30 to 60 minutes. There are now, in development, some extracts that are used as a sublingual, or beneath the tongue spray. It's claimed by the company that's developing it that that reaches the brain within 10 to 20 minutes, however it seems that a lot of it actually ends up being swallowed and absorbed through the gut, so there's a least a sizeable portion of that that has a delayed onset.

How long will THC show up in a urine test after using marijuana?

The length of time that THC shows up in the blood is also variable, depending on the duration, and chronicity of use. If an individual just uses it once, or occasionally, say once every several weeks, then it's usually cleared from the body to the point that it's not detectable in the usual drug screens, after one to two weeks. However, if you've been a long-term user, THC is fat soluble: it can get deposited in the 'fat stores' in the body, and then slowly come out, and it's estimated then a person can be positive for THC a month, or even longer after they stop using, if they've been a chronic user for any length of time prior to that.

What are some of the byproducts of marijuana?

Well, there are many other cannabinoids present. They are not present at the same concentrations as either THC or Dranabinol or Cannabidiol, but we really don't know much about those compounds. Like any smoked vegetable matter, there is all kinds of combustion product. There's ash. There is whatever the plant has been treated with or fed with. You have the general set of compounds. You have tar. You don't have nicotine, which differs from cigarettes. But you have the usual set of compounds that come from burning plant material. For that reason, there has been a big push lately to develop vaporization systems that heat the material high enough and rapidly enough, so that psychoactive cannabinoids are released, but there is no burning of the cannabis leaf itself. And so, the amount of noxious particles that are produced is minimized.

Is there any reliable scientific evidence that marijuana has medical value?

Absolutely, you know we live in a time of science based and evidenced based clinical care, so I don't think anybody would be recommending cannabis for patients unless there was a good science base. In particular we have recently performed studies that are placebo controlled, double blind studies using federally contracted grown and distributed marijuana for research purposes. And this has been shown to both be an effective analgesic, or pain reliever for peripheral neuropathy of various sources including HIV. It's been shown to be very good at increasing the appetite and suppressing the nausea secondary to cancer treatments, chemotherapy, radiation treatments. I don't know if there are double blind studies but there's certainly a lot of anecdotal evidence that is useful in Multiple Sclerosis, Lou Gehrig's disease and a number of other musculo-skeletal diseases that involve muscle spasms and pain. And the list goes on and on, but I think most of the placebo-controlled studies of whole cannabis are in the analgesic area. There's also been a large amount of research done in Canada, which has a federally legislated medical cannabis system for the entire country. The government even contracts to grow and supply standardized high quality cannabis to patients who have registered in the system. And researchers at the University of Toronto and McGill in Montreal and so forth have done a lot more studies, actually hundreds of studies in various conditions, mostly pain conditions.

What are some of the disadvantages of using opiates as a treatment for ailments?

An opiate is any drug that is derived from or synthesized from morphine. Opium is the original source hence the name opiate. These are ancient treatments for pain and they remained the backbone of treatment of chronic persistence of your pain, but they have a very serious addiction potential. There is always the possibility that someone treated for chronic periods of time for chronic pain will become more and more dependent and will also require higher doses of opiates, which eventually can lead to respiratory failure and death. In contrast, the cannabinoids work through a different set of receptors, the cannabinoid receptors. Where as the opiates work through the endorphin system and the opiate receptors in the brain. These do not appear to cause the kind of insensitivity and need for increasing doses that lead to addiction of the opiates.

What is 'Sativex'?

Sati vex is an attempt to harness whole extract from medical cannabis. A company in England has bred various strains of cannabis to produce several, one which is very high in THC, another one of which is very high in cannabadiol and these two different extracts are being tested by them in a sublingual spray form as rapid acting and more natural extract rather than the synthetic compounds that can be used for the same purposes as medical cannabis.